dm.h

  1/*
  2 * Internal header file for device mapper
  3 *
  4 * Copyright (C) 2001, 2002 Sistina Software
  5 * Copyright (C) 2004-2006 Red Hat, Inc. All rights reserved.
  6 *
  7 * This file is released under the LGPL.
  8 */
  9
 10#ifndef DM_INTERNAL_H
 11#define DM_INTERNAL_H
 12
 13#include <linux/fs.h>
 14#include <linux/device-mapper.h>
 15#include <linux/list.h>
 16#include <linux/moduleparam.h>
 17#include <linux/blkdev.h>
 18#include <linux/backing-dev.h>
 19#include <linux/hdreg.h>
 20#include <linux/completion.h>
 21#include <linux/kobject.h>
 22#include <linux/refcount.h>
 23#include <linux/log2.h>
 24
 25#include "dm-stats.h"
 26
 27/*
 28 * Suspend feature flags
 29 */
 30#define DM_SUSPEND_LOCKFS_FLAG		(1 << 0)
 31#define DM_SUSPEND_NOFLUSH_FLAG		(1 << 1)
 32
 33/*
 34 * Status feature flags
 35 */
 36#define DM_STATUS_NOFLUSH_FLAG		(1 << 0)
 37
 38/*
 39 * List of devices that a metadevice uses and should open/close.
 40 */
 41struct dm_dev_internal {
 42	struct list_head list;
 43	refcount_t count;
 44	struct dm_dev *dm_dev;
 45};
 46
 47struct dm_table;
 48struct dm_md_mempools;
 49struct dm_target_io;
 50struct dm_io;
 51
 52/*
 53 *---------------------------------------------------------------
 54 * Internal table functions.
 55 *---------------------------------------------------------------
 56 */
 57void dm_table_event_callback(struct dm_table *t,
 58			     void (*fn)(void *), void *context);
 59struct dm_target *dm_table_find_target(struct dm_table *t, sector_t sector);
 60bool dm_table_has_no_data_devices(struct dm_table *table);
 61bool dm_table_is_wildcard(struct dm_table *t);
 62int dm_calculate_queue_limits(struct dm_table *table,
 63			      struct queue_limits *limits);
 64int dm_table_set_restrictions(struct dm_table *t, struct request_queue *q,
 65			      struct queue_limits *limits);
 66struct list_head *dm_table_get_devices(struct dm_table *t);
 67void dm_table_presuspend_targets(struct dm_table *t);
 68void dm_table_presuspend_undo_targets(struct dm_table *t);
 69void dm_table_postsuspend_targets(struct dm_table *t);
 70int dm_table_resume_targets(struct dm_table *t);
 71enum dm_queue_mode dm_table_get_type(struct dm_table *t);
 72struct target_type *dm_table_get_immutable_target_type(struct dm_table *t);
 73struct dm_target *dm_table_get_immutable_target(struct dm_table *t);
 74struct dm_target *dm_table_get_wildcard_target(struct dm_table *t);
 75bool dm_table_request_based(struct dm_table *t);
 76bool dm_table_supports_size_change(struct dm_table *t, sector_t old_size,
 77				   sector_t new_size);
 78
 79void dm_lock_md_type(struct mapped_device *md);
 80void dm_unlock_md_type(struct mapped_device *md);
 81enum dm_queue_mode dm_get_md_type(struct mapped_device *md);
 82struct target_type *dm_get_immutable_target_type(struct mapped_device *md);
 83
 84int dm_setup_md_queue(struct mapped_device *md, struct dm_table *t);
 85
 86/*
 87 * To check whether the target type is bio-based or not (request-based).
 88 */
 89#define dm_target_bio_based(t) ((t)->type->map != NULL)
 90
 91/*
 92 * To check whether the target type is request-based or not (bio-based).
 93 */
 94#define dm_target_request_based(t) ((t)->type->clone_and_map_rq != NULL)
 95
 96/*
 97 * To check whether the target type is a hybrid (capable of being
 98 * either request-based or bio-based).
 99 */
100#define dm_target_hybrid(t) (dm_target_bio_based(t) && dm_target_request_based(t))
101
102/*
103 * Zoned targets related functions.
104 */
105int dm_set_zones_restrictions(struct dm_table *t, struct request_queue *q,
106		struct queue_limits *lim);
107int dm_revalidate_zones(struct dm_table *t, struct request_queue *q);
108void dm_finalize_zone_settings(struct dm_table *t, struct queue_limits *lim);
109void dm_zone_endio(struct dm_io *io, struct bio *clone);
110#ifdef CONFIG_BLK_DEV_ZONED
111int dm_blk_report_zones(struct gendisk *disk, sector_t sector,
112			unsigned int nr_zones,
113			struct blk_report_zones_args *args);
114bool dm_is_zone_write(struct mapped_device *md, struct bio *bio);
115int dm_zone_get_reset_bitmap(struct mapped_device *md, struct dm_table *t,
116			     sector_t sector, unsigned int nr_zones,
117			     unsigned long *need_reset);
118#define dm_has_zone_plugs(md) ((md)->disk->zone_wplugs_hash != NULL)
119#else
120#define dm_blk_report_zones	NULL
121static inline bool dm_is_zone_write(struct mapped_device *md, struct bio *bio)
122{
123	return false;
124}
125#define dm_has_zone_plugs(md) false
126#endif
127
128/*
129 *---------------------------------------------------------------
130 * A registry of target types.
131 *---------------------------------------------------------------
132 */
133int dm_target_init(void);
134void dm_target_exit(void);
135struct target_type *dm_get_target_type(const char *name);
136void dm_put_target_type(struct target_type *tt);
137int dm_target_iterate(void (*iter_func)(struct target_type *tt,
138					void *param), void *param);
139
140int dm_split_args(int *argc, char ***argvp, char *input);
141
142/*
143 * Is this mapped_device being deleted?
144 */
145int dm_deleting_md(struct mapped_device *md);
146
147/*
148 * Is this mapped_device suspended?
149 */
150int dm_suspended_md(struct mapped_device *md);
151
152/*
153 * Internal suspend and resume methods.
154 */
155int dm_suspended_internally_md(struct mapped_device *md);
156void dm_internal_suspend_fast(struct mapped_device *md);
157void dm_internal_resume_fast(struct mapped_device *md);
158void dm_internal_suspend_noflush(struct mapped_device *md);
159void dm_internal_resume(struct mapped_device *md);
160
161/*
162 * Test if the device is scheduled for deferred remove.
163 */
164int dm_test_deferred_remove_flag(struct mapped_device *md);
165
166/*
167 * Try to remove devices marked for deferred removal.
168 */
169void dm_deferred_remove(void);
170
171/*
172 * The device-mapper can be driven through one of two interfaces;
173 * ioctl or filesystem, depending which patch you have applied.
174 */
175int dm_interface_init(void);
176void dm_interface_exit(void);
177
178/*
179 * sysfs interface
180 */
181int dm_sysfs_init(struct mapped_device *md);
182void dm_sysfs_exit(struct mapped_device *md);
183struct kobject *dm_kobject(struct mapped_device *md);
184struct mapped_device *dm_get_from_kobject(struct kobject *kobj);
185
186/*
187 * The kobject helper
188 */
189void dm_kobject_release(struct kobject *kobj);
190
191/*
192 * Targets for linear and striped mappings
193 */
194int linear_map(struct dm_target *ti, struct bio *bio);
195int dm_linear_init(void);
196void dm_linear_exit(void);
197
198int stripe_map(struct dm_target *ti, struct bio *bio);
199int dm_stripe_init(void);
200void dm_stripe_exit(void);
201
202/*
203 * mapped_device operations
204 */
205void dm_destroy(struct mapped_device *md);
206void dm_destroy_immediate(struct mapped_device *md);
207int dm_open_count(struct mapped_device *md);
208int dm_lock_for_deletion(struct mapped_device *md, bool mark_deferred, bool only_deferred);
209int dm_cancel_deferred_remove(struct mapped_device *md);
210int dm_request_based(struct mapped_device *md);
211int dm_get_table_device(struct mapped_device *md, dev_t dev, blk_mode_t mode,
212			struct dm_dev **result);
213void dm_put_table_device(struct mapped_device *md, struct dm_dev *d);
214
215int dm_kobject_uevent(struct mapped_device *md, enum kobject_action action,
216		      unsigned int cookie, bool need_resize_uevent);
217
218int dm_io_init(void);
219void dm_io_exit(void);
220
221int dm_kcopyd_init(void);
222void dm_kcopyd_exit(void);
223
224/*
225 * Mempool operations
226 */
227void dm_free_md_mempools(struct dm_md_mempools *pools);
228
229/*
230 * Various helpers
231 */
232unsigned int dm_get_reserved_bio_based_ios(void);
233
234#define DM_HASH_LOCKS_MAX 64
235
236static inline unsigned int dm_num_hash_locks(void)
237{
238	unsigned int num_locks = roundup_pow_of_two(num_online_cpus()) << 1;
239
240	return min_t(unsigned int, num_locks, DM_HASH_LOCKS_MAX);
241}
242
243#define DM_HASH_LOCKS_MULT  4294967291ULL
244#define DM_HASH_LOCKS_SHIFT 6
245
246static inline unsigned int dm_hash_locks_index(sector_t block,
247					       unsigned int num_locks)
248{
249	sector_t h1 = (block * DM_HASH_LOCKS_MULT) >> DM_HASH_LOCKS_SHIFT;
250	sector_t h2 = h1 >> DM_HASH_LOCKS_SHIFT;
251
252	return (h1 ^ h2) & (num_locks - 1);
253}
254
255#endif